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

With annotations only declaring the generic safety profile (destructive, idempotent, open-world), the description carries the important specifics: creator-only authorization, bearer-token requirement in the Authorization header, patch semantics (only supplied fields change), null-clearing of nullable fields, and replacement semantics for arrays/metadata. This is exactly the non-obvious behavior an agent needs and is not derivable from the annotations or schema.

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?

Four compact sentences, zero filler, front-loaded with the access constraint and then the mutation semantics. Every sentence adds distinct information.

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?

An output schema exists so return values need no explanation, and the annotations cover safety. The description supplies auth, preconditions, and patch/clear/replace semantics, leaving only minor gaps such as error behavior for non-creators and the meaning of individual change fields.

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 0% and the nested 'changes' object has five sub-fields (body, tags, title, status, metadata_json) with no per-field documentation. The description compensates with valuable patch semantics — null clears nullable fields, arrays and metadata replace — but does not explain field meanings, the status enum, or which fields are nullable.

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 name and title ('Edit a discussion you created') plus 'Only the creator may edit' make the verb and resource unambiguous. However, the description never restates the action or distinguishes itself from close siblings like create_thread, read_thread, and reply_to_thread — it assumes the reader infers the difference from the name.

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 gives real preconditions — creator-only authorship and 'Provide at least one field' — which implies when the tool is applicable. It stops short of naming alternatives (e.g., reply_to_thread for adding content, read_thread for viewing) or stating when not to use it.

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