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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds the status taxonomy (active/merged/closed) and the project-context requirement, which goes beyond the schema. Minor gap: no mention of pagination or result limits for a browsing tool, but annotations carry the safety burden.

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?

Three sentences, front-loaded with the core purpose, then usage routing, then prerequisite. No wasted words; every sentence earns its place.

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 simple read-only list tool with 100% schema coverage and readOnlyHint annotation, the description covers purpose, usage routing, and prerequisite. It omits pagination/limit behavior, which could matter when browsing, but this is minor against the strong overall coverage.

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 both parameters are fully documented in the schema. The description adds the 'draft version' clarification and the project-context requirement, which slightly enriches parameter meaning, but the schema carries the heavy lifting. Baseline 3 is appropriate.

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?

States a specific verb (List), resource (branches of a draft version), and the returned statuses (active, merged, closed). It explicitly names the sibling get_branch as the alternative for single-branch diff, distinguishing the two without ambiguity.

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?

Gives explicit when-to-use guidance: browse branches or find a branch id, and explicitly routes to get_branch for a single branch with diff. Also notes the project context prerequisite, leaving nothing to inference.

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