github_list_branches

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered structurally. The description adds only a return-value summary (head commit sha) that output_schema already provides, and says nothing about pagination behavior via 'limit', rate limits, or error cases.

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?

A single front-loaded sentence with zero filler. It is efficient, though so short that it reads as a title restatement rather than a purposeful briefing.

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 tool with an optional repo default and an undocumented 'limit' parameter, the description omits the default-repo fallback, pagination/capping semantics, and ordering of results. Since output_schema exists, repeating the return field is redundant while real gaps remain unaddressed.

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 50%: 'repo' is documented (owner/name plus default fallback) but 'limit' has no description anywhere. The description never mentions 'limit' or that it caps the number of branches returned, leaving the one undocumented parameter unexplained in both places.

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 ('List branches') plus the key returned field (head commit sha), so the agent knows exactly what it retrieves. It doesn't explicitly contrast with siblings, but the resource is distinct from github_list_tags and github_list_pull_requests, making intent 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?

There is no guidance on when to call this versus alternatives, no mention of prerequisites (e.g., needing an authenticated repo context), and no note that omitting 'repo' falls back to a default. The agent must infer everything about usage from the name.

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