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

Annotations only declare readOnlyHint=false, destructiveHint=false, openWorldHint=false; the description goes well beyond that, disclosing the side effects (installs the pinned hook binary, writes config, merges settings, installs credentials) and the follow-up obligation to commit what it stages. That is exactly the mutation context an agent needs.

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 and the once-per-repo constraint before the procedural detail. Dense but every sentence carries information; the parenthetical enumerating the command's effects is slightly packed but earned.

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?

There is no output schema, and the description correctly covers what is returned ('the command or the files, and what they install'). Combined with annotations covering the safety profile, an agent has enough to call it correctly; only the already-configured case is 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 description coverage is 100%, with repo_id and the enforce/advisory/files mode values already documented in the schema. The description reinforces the files path but adds no new syntax, format, or default semantics beyond what the schema provides, so the baseline 3 applies.

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: set up Collide in a repo, and adds the strong qualifier 'once per repo'. It also previews the two output shapes (a command vs files), so an agent knows what the call produces. It does not explicitly contrast with siblings, but none of them (blast_radius, claim, recall, etc.) overlap with setup.

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 a clear invocation condition ('once per repo') and branching guidance: run install.command exactly as given at the repo root if present, otherwise write the returned files and commit. It does not spell out when setup should be skipped (e.g. already configured), so a small gap remains.

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