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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds substantial operational context beyond them: async job submission with polling (5-30s), the quota cost per call, and the caveat that observations 'do not prove live links'. It does not detail failure/error behavior or quota-exhaustion handling, which keeps it short of a 5.

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?

Front-loads the purpose, then layers behavior, cost, and a caveat in three tight sentences with no redundancy. Every sentence carries distinct information an agent needs.

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?

Complete for a two-parameter async tool: the description discloses latency, polling behavior, cost, output shape, and a data-quality caveat, and an output schema exists so return structure need not be re-explained. Nothing essential for correct invocation is missing.

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 100% and both parameters are already documented, so the baseline is 3. The description reinforces that competitor_domains holds 'one or more of your competitors' and explains the found_on output field, but adds no format, syntax, or validation meaning beyond the schema.

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 (competitor backlink gap analysis) and defines the exact result set: domains linking to one or more competitors but not to you. This clearly distinguishes it from sibling tools like backlinks and gap_outreach_targets without needing to open either 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 by the described output rather than stated: you run it when you want a gap list. The quota note ('costs one gap job against the monthly quota') gives decision-relevant context, but there is no explicit when-to-use/when-not or mention of alternatives such as gap_outreach_targets as the logical follow-up.

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