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

Goes well beyond the annotations: 1 MB text cap, 256 KB page size with next_offset continuation, binary files returned as metadata only, the response naming the exact commit read, and an explicit untrusted-content/never-instructions trust boundary. These are exactly the traits annotations do not cover.

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 dense sentences with zero filler, front-loading the file/directory duality and the ref default before the paging and trust details. Every clause carries operational weight.

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 five-parameter read tool with full schema coverage, annotations and an output schema, the description fills the remaining gaps — paging, binary handling, commit provenance, and the untrusted-data warning. Nothing needed to call it correctly is missing.

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%, so the schema already documents ref, path, offset, and recursive. The description reinforces the ref default, the 1 MB/256 KB paging model behind offset, and the text-vs-binary behavior, but adds no syntax or format detail the schema lacks. 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 — 'Read a file or list a directory of the repository connected to a room' — and the scoping to a branch/tag/commit. An agent can distinguish this from message-reading siblings like city_room_read or city_room_search without opening any schema.

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 makes the triggering context implicit (read repo content at a ref) and gives operational guidance (default branch, pagination via next_offset), but never names an alternative tool or states when not to use this one. With many city_room_* siblings, an explicit contrast with city_room_read/city_room_search would have earned a higher score.

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