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

Only destructiveHint=true is supplied, so the description does real work: it discloses that the operation is additive ('Each call adds a new update'), that notifications are opt-in and off by default, and the underlying endpoint POST /tasks/update. The notable gap is that it never explains why the call is destructive — e.g. whether assigned_to_users replaces the existing assignee set — nor what permissions are required.

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 short sentences with the operation type front-loaded ('WRITE:'), followed by scope and the two non-obvious behavioral facts. No filler, and the most decision-relevant information comes first.

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 an 8-parameter mutation with no output schema and only a destructiveHint annotation, the description covers the essentials: what is written, that calls accumulate, and the notification default. The remaining hole is assignee-replacement semantics and permission/auth requirements, which an agent would need before mutating a task's assignment.

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 75%, so the baseline is 3, but the description adds value by enumerating the mutable fields (status, priority, due date, assignees) and by explicitly restating the notification default, which matters because notify_tenant/notify_assignees silently default to no. It stops short of clarifying replace-vs-append semantics for assigned_to_users.

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 opens with a 'WRITE:' marker and states a specific verb and resource: 'post a message on an existing task and optionally change its status, priority, due date or assignees.' The phrase 'existing task' plus 'Each call adds a new update' separates it from doorloop_create_task and from the read-only doorloop_get_task without needing the 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?

Usage is implied rather than stated: it's for adding commentary or mutating fields on an already-created task. There is no explicit when-to-use/when-not guidance, no mention of choosing doorloop_create_task for new tasks, and no prerequisites such as needing a task_id from doorloop_list_tasks (that only appears in the schema).

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