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

Annotations already declare readOnlyHint=false, destructiveHint=true and idempotentHint=true, so the safety profile is covered structurally. The description adds little beyond a redundant 'WRITE:' prefix and the HTTP endpoint; it does not say whether completion is reversible, what permissions are needed, or what happens on an already-completed task (idempotent behavior is only in annotations).

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?

Single front-loaded sentence with the write nature flagged first, plus a terse endpoint. No filler, though the endpoint string is arguably duplicated by the description's own wording.

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 one-parameter mutation with rich annotations and no output schema, the definition covers what an agent needs to invoke it correctly. The remaining gap is behavioral detail (permissions, reversibility), which annotations partially cover.

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?

With only one parameter and 100% schema description coverage, the schema carries the semantics (type, length bounds). The description merely restates that the task code is the key, adding no format detail such as whether it accepts a numeric ID or prefixed code format.

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 ('Mark a task as completed') plus the identifier required ('by its task code'), which cleanly separates it from siblings like getfly_create_task, getfly_get_task and getfly_list_tasks. The endpoint is a bonus confirmation of the operation.

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: 'mark as completed by task code' makes the input precondition obvious, but there is no explicit when/when-not guidance and no named alternative (e.g., a general update_task tool is not referenced). Adequate for a single-purpose verb, but leaves routing mostly to inference.

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