git_blame_chunk

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

With no annotations, the description carries the burden. It discloses 'computed lazily and cached' and 'hash-bound', but doesn't mention read-only nature, potential cost, or what happens on missing chunk. It's some transparency but not comprehensive.

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?

One sentence, front-loaded with purpose. Loses a point for being slightly vague in wording (hash-bound, lazily) but overall efficient.

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?

Tool is simple (2 params, 1 required), but no output schema and description doesn't explain return format or caching lifetime. Meets minimal bar but has gaps.

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 has 50% coverage (worktree has a description). The description doesn't explain chunk_id beyond 'one chunk'. Baseline 3 for high coverage, but here coverage is 50% and description adds nothing about params, so it's below baseline.

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 clearly states the verb+resource:

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 it is for a single chunk via 'for one chunk', but gives no guidance on when to prefer this over other tools like git_history_for_path or commit_search, and no mention of exclusions or prerequisites.

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