results_summary

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

With no annotations, the description carries the full burden for disclosing behavior. It openly explains what is returned (counts, variables, per-variable statistics) and the optional variable restriction. It does not mention edge cases (e.g., invalid file, unsupported format), but for a summarization tool the core behavior is transparent enough.

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

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

The description is a single, well-structured sentence that packs all key information: resource, what is summarized, and the optional restriction. No redundant or misleading words.

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

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

Given the presence of an output schema, the description does not need to detail return values. It covers the essential inputs and behavior, and is sufficiently complete for a straightforward summarization tool. It could add caveats about file access or variable name syntax, but these are not critical for a summary function.

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

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

Schema description coverage is 0%, so the description must compensate. It adds meaningful context to both parameters: 'VTK/VTU result file' clarifies the expected file type, and 'optionally restrict to one variable' explains the purpose of the variable parameter. This goes beyond the basic schema by giving usage context, though it does not specify exact path formats or validation rules.

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

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

The description states a specific verb ('Summarise') and resource ('VTK/VTU result file'), and enumerates the exact summary contents (points/cells, variables, per-variable statistics). It clearly distinguishes itself from sibling tools like results_probe or results_list by focusing on aggregated statistics.

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

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

The description implies usage through its purpose but does not explicitly state when to choose this tool over siblings such as results_list or results_probe. There is no mention of alternatives or conditions like 'use for overview, use results_probe for point sampling.' This is a clear but implicit usage context.

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