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

Beyond the readOnlyHint and idempotentHint annotations, the description discloses the fallback behavior when repositoryId is unknown, the required credentials and scope (DEVOPS_ORG_URL + DEVOPS_PAT with Code: Read scope), and the returned fields. This adds meaningful behavioral context that annotations alone do not provide.

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 longer than average but every sentence earns its place: trigger phrases, an explicit alternative exclusion, core functionality, repositoryId handling, filters, return values, related tool, and auth requirements. The priority trigger is front-loaded, ensuring the agent immediately knows when to call this tool.

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?

For a list PR tool with six fully documented parameters and no output schema, the description is complete. It covers invocation triggers, filtering options, repositoryId behavior, expected return fields, authentication needs, and the natural follow-up tool. Nothing essential for an agent to call it correctly is missing.

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 coverage is 100%, so the baseline is 3. The description adds valuable semantics beyond the schema: it explains how to handle an unknown repositoryId (omit it to list all repositories) and clarifies the filter semantics (status, author display name, target branch). This nudges it above the baseline, though it doesn't add details for every parameter.

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 starts with a specific verb and resource: 'List Pull Requests in an Azure DevOps Git repository.' It also states the exact output (PR ID, title, author, source->target branch, review status, linked work items, creation date) and clearly distinguishes itself from search_d365_code and ado_analyze_pr_impact. This makes the tool's role unambiguous.

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 provides an explicit priority trigger list of user phrases and a direct exclusion: 'NEVER call search_d365_code for PR listing requests.' It also routes follow-up analysis to ado_analyze_pr_impact. This is outstanding guidance for when to use the tool versus alternatives.

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