Server Quality Checklist

Tool Scores

• issuesA
  3.7/5.0
  Behavior5/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations, the description carries the full burden and does an excellent job. It discloses that the tool executes a CLI command, details the exact return dictionary structure (return_code, status, output, command, working_directory), explains timeout and failure behavior, and explicitly lists ToolError conditions including partial output collection. It also documents path resolution and the dry-run flag behavior.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness3/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is well-organized into Args, Returns, and Raises sections, but it is long and repeats much of what the schema already provides. It also includes a 'ctx' parameter in the Args list that is not present in the input schema, which could confuse an agent. The extra noise and redundancy reduce the clarity that good structure would otherwise provide.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness4/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  For a tool with 9 optional parameters and no annotations, the description is nearly complete: it covers all parameters, return values, and error conditions. The output schema is indicated as present, so the detailed Returns section is a bonus. The only notable gaps are the lack of guidance relative to sibling tools and the minor working_directory default discrepancy, but these do not leave an agent unable to call the tool correctly.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters4/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 100%, so the baseline is 3. The description adds meaningful extra semantics beyond the schema: it explains that `path` searches system PATH and DIFFBLUE_COVER_CLI, that `dcover_timeout` defaults to 600 and setting None is not recommended, and that `dry_run` passes the '--dry-run' flag. There is a slight inconsistency for `working_directory` (description says defaults to current working directory while schema shows default '/app'), which prevents a 5.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose4/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description opens with 'Invoke Diffblue Cover to identify project issues,' which provides a specific verb, resource, and outcome. It clearly says the tool runs the `dcover issues` command and outputs a prioritized list of issues. However, it does not explicitly differentiate itself from the sibling tools 'create' and 'refactor', which are likely also Diffblue commands.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description gives no explicit guidance on when to use this tool versus alternatives. It implies a pre-test-generation use case with 'issues that may prevent test generation,' but it never mentions create or refactor as alternatives or states conditions for choosing one. An agent must infer the appropriate context.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• createA
  4.2/5.0
  Behavior4/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  No annotations are provided, so the description carries the full behavioral disclosure burden. It thoroughly explains that this executes an external CLI, what the return structure is, what errors may occur, how timeouts are handled, and that environment variables can override options. It could explicitly mention filesystem side effects such as writing generated test files, but overall the behavior is well disclosed.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is long but well organized into Args, Returns, Raises, and Notes sections. The leading purpose statement is clear and the subsequent detail is structured rather than a wall of text. A small amount of redundancy exists with return values repeated from the output schema, but it remains efficient for a complex CLI tool.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the tool wraps an external CLI, the description is remarkably complete: it covers parameters, defaults, environment overrides, license requirements, error behavior, timeout semantics, and exact return fields. The output schema already exists, and the description still adds the important operational details an agent needs to invoke this tool correctly. Nothing essential is missing.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters4/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The input schema has 100% coverage of parameters, so the baseline is 3. The description adds meaningful detail beyond the schema: path searching behavior including DIFFBLUE_COVER_CLI, working_directory defaulting behavior, the implication of timeout=None, fully-qualified entry_point examples, and the effect of DIFFBLUE_COVER_OPTIONS. This elevates parameter understanding beyond the schema alone.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly identifies the tool as invoking Diffblue Cover to generate unit tests for Java code. The first sentence states a specific action and resource, and distinguishes this 'create' tool from the sibling tools 'refactor' and 'issues' by focusing on test generation.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines3/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description implies when to use the tool: when you want to generate unit tests for Java code with dcover. However, it does not explicitly discuss when not to use it or how it compares to the sibling tools 'refactor' and 'issues'. The usage context is clear but alternative selection guidance is missing.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• refactorA
  4.4/5.0
  Behavior4/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations provided, the description carries the full behavioral burden and does well: it explains that the command applies changes, that `dry_run` checks readiness without applying changes, that timeouts default to 600 seconds and can be disabled, and that failures raise `ToolError` with partial output. It does not explicitly mention file-system side effects, but 'apply automated refactorings' implies mutation clearly enough.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is well-structured with clear sections for overview, arguments, return value, and errors. It is somewhat redundant with the schema's parameter descriptions, but the added details earn their place and the opening sentence front-loads the core purpose.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  The description is complete for this CLI-wrapper tool: it covers the command being run, all parameter defaults and behaviors, the return structure, and failure modes. An agent has everything needed to invoke the tool correctly without relying on external documentation.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters4/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 100%, so the baseline is 3. The description adds meaningful value beyond the schema by explaining that `path` searches the system PATH and the DIFFBLUE_COVER_CLI environment variable, that `dcover_timeout=None` disables the timeout, and that `dry_run` avoids applying changes. These details help an agent call the tool correctly.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states a specific verb and resource: 'Invoke Diffblue Cover to refactor the project' and identifies the exact command executed (`dcover refactor`). It also gives concrete example use cases ('fixing build issues or adding missing dependencies'), which makes the tool's purpose unmistakable and distinct from the sibling tools.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description provides clear context for when to use the tool: applying automated refactorings, fixing build issues, or adding missing dependencies. It does not explicitly contrast with the sibling tools `create` and `issues`, but it gives enough purpose-based guidance for an agent to select it appropriately.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.