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

Adds substantial context beyond the annotations: it names the exact failure codes (BILLING_INACTIVE, MONTHLY_CAP_REACHED) and the `tellHuman` response field, and instructs the agent not to silently degrade. It omits success-path behavior, such as what is returned or whether re-attaching the same URL creates duplicates (annotations mark idempotentHint=false but the description never addresses that).

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?

The purpose is front-loaded in the first clause, and the billing warning, while emphatic and long, carries actionable instructions that would otherwise be lost. Some of the capitalized admonishment could be trimmed without losing information.

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 and low parameter coverage, the description handles the failure mode thoroughly but leaves gaps: no success return shape, no parameter meanings, no mention of non-idempotency despite the annotation.

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 33% and the description adds no meaning to any of the three parameters. Notably `title` is optional and unexplained — an agent cannot tell whether it labels the link or overrides something else — and `url` has no format or validation guidance.

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 ('Attach a link (URL) to an issue'), which naturally separates it from save_attachment_file and prepare_attachment_upload. It does not explicitly name those siblings, so it falls 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?

Gives strong guidance for one narrow scenario — what to do when the call is refused for billing — but says nothing about when to choose this tool over save_attachment_file or prepare_attachment_upload, nor any prerequisites like issue permissions.

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