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

Annotations only carry destructiveHint=true, so the description must add context. It does disclose the accepted content format ('content may contain basic HTML') and the underlying API operation (POST /api/comments), which is useful. However, it says nothing about required permissions, whether a posted comment can be edited or removed, or what the response contains — meaningful gaps for a mutation tool.

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, front-loaded with the action and resource, then the format caveat, then the read alternative. Nothing is redundant and no sentence wastes space.

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 two-parameter mutation tool with no output schema and thin annotations, the description covers the action, content format, related read tool, and the backing endpoint. It leaves out permission/auth requirements and return behavior, which keeps it just short of fully complete.

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 100% and both parameters are documented, so the baseline is 3. The description adds real meaning beyond the schema by specifying that the content field accepts basic HTML, which the schema's 'Comment text.' does not convey. It adds no further detail on task_id beyond what the schema states.

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 precise verb + resource + location: 'Add a comment to a task's discussion thread.' It is clearly distinct from sibling tools like paymo_update_task or paymo_create_task, and it names paymo_get_task as the read counterpart, so an agent can place it without opening a 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?

Gives explicit routing guidance for the counterpart operation ('Read existing comments with paymo_get_task include=thread.comments'), which is genuinely actionable. It does not state prerequisites (task must exist, permissions needed) or when *not* to comment, so it stops short of full when/when-not coverage.

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