cos_graph_diff

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, which cover safety. The description adds context by detailing the use of `git diff --name-only`, mapping to symbols and downstream consumers, and the ability to walk transitive consumers, which goes beyond the annotation baseline.

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 well-structured: a one-line summary, a method paragraph, an Args list, and a Returns section. Every sentence contributes to understanding, with no unnecessary repetition or fluff.

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?

Given the tool's moderate complexity and the presence of an output schema, the description is sufficiently complete. It explains the workflow, parameters, and return envelope keys, and provides enough context for an agent to select and invoke the tool, though it could benefit from a brief example or note on interpreting risk_level.

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?

The input schema has 0% description coverage, but the description compensates with an Args section that explains each parameter (base, head, analyze_downstream) and provides defaults and semantics. This adds meaningful value beyond the schema.

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 tool's function: 'Graph blast-radius of a git revision range (base..head)' with a specific verb and resource. It further explains the process and output, distinguishing it from sibling graph tools that focus on other analyses.

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 usage context via 'PR/review view' but does not explicitly state when to use this tool over alternatives or mention any exclusions. No sibling tool is named as a fallback or alternative, leaving some ambiguity.

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