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

The annotations already declare this is a non-read, non-destructive, non-idempotent, closed-world write. The description adds genuinely new behavior the annotations cannot express: visibility is internal only and nothing reaches the customer, plus the scope needed to call it. The notable gap is that idempotentHint=false is never surfaced — the agent is not warned that a retry could post a duplicate comment.

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?

Two short sentences, front-loaded with what the tool does and the visibility constraint before the scope/sibling context. Every clause conveys distinct information; there is no restatement of the title or filler.

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?

Return values need not be explained because an output schema exists, and annotations carry the safety profile, so the description covers the remaining essentials: audience, permission scope, and relationship to update_task. It is slightly incomplete in leaving parameter formats and duplicate-on-retry behavior unaddressed for a write tool.

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 description says nothing about either parameter, so it compensates for none of the gap. It never mentions that task_id must be a numeric string or that body is capped at 4000 characters and is required and non-empty. Only the self-evident parameter names carry any meaning.

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 pairs a specific verb with a specific resource ("Add an internal comment to a task") and pins down the audience (team-only in the Spun app, never sent to a customer). It also contrasts the operation with update_task on the same object, so the agent can separate it from delete/edit-style task operations. It does not explicitly name list_task_comments as the read counterpart, which keeps it just short of a 5.

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 the operative precondition (requires the manage_tasks scope) and frames commenting as a lighter-weight write than update_task, which is a usable selection hint between the two. It stops short of stating exclusions, e.g. when a comment is inappropriate versus a task update or a customer-facing reply via draft_reply.

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