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

Annotations already declare readOnlyHint=true, so the safety profile is covered. Beyond that, the description discloses return content (sha, default/protected flags) which is the only source of return information since no output schema exists, adding real behavioral value.

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?

Two tight sentences, front-loaded with what the tool returns, followed by the filter semantics. Every clause earns its place with no filler.

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 two-parameter read-only listing tool with full schema coverage, the description covers purpose, filter semantics, and return fields. The one gap is that it never routes the agent away from the closely named branch_list/branch_name siblings.

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 baseline is 3, but the description adds meaning beyond the schema's terse 'Branch name substring' by showing that a task ID like '#26388' resolves to that task's live branch — a non-obvious matching semantic the schema does not convey.

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 and resource ('Lists repository branches') plus the attributes returned (sha, default/protected flags). However, it never distinguishes itself from the sibling tools branch_list and branch_name, leaving the agent to guess which branch-listing tool to pick.

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?

Usage is only implied: the search example ('#26388' finds the live branch of that task) hints at when to use the filter, but there is no explicit when-to-use statement, no exclusions, and no mention of the alternative branch_list sibling.

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