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

Beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false), it discloses concrete behavioral traits: a hard cap of 10 assignees per thread, the constraint that only repo readers can be assigned, the required 'repo' scope plus write access, and the exact return shape. These are meaningful operational facts not present in structured fields, and idempotentHint is consistent with the assign semantics.

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?

Front-loaded with the core action and reverse mode, then layers constraints, parameters, and return shape efficiently. It is dense and slightly packed with migration trivia, but essentially every clause carries information an agent needs.

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 mutation tool with no output schema, the description covers permissions, limits, parameter conventions, and the response structure, and the annotations cover the safety profile. An agent has everything required to invoke it correctly.

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 coverage is only 57%, but the description compensates by explaining the assignee-vs-assignees alternative, the type default ('issue' or 'pull_request'), and the remove flag. The three required params (owner, repo, number) are self-descriptive by name, so little is left ambiguous.

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 (assign/unassign) and resource (users on an issue or PR), and the parenthetical 'remove: true' immediately disambiguates the reverse operation. It is clearly separable from siblings like gluecron_label_issue and gluecron_comment_issue 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?

Explains the in-tool branch (remove: true to unassign) and the migration away from `assignee:<username>` labels, giving clear operational context. It does not, however, name an alternative tool or an explicit when-not-to-use condition, so it stops short of full routing guidance.

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