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

Annotations already cover readOnly, idempotent, openWorld and non-destructive, yet the description adds substantive behavior: the conditional `licensing` payload fields, the no-vendor-request guarantee, and the untrusted-source delimiter wrapping with prompt-injection guidance. This is well beyond what structured fields provide.

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 tight sentences, front-loaded with the primary return contract, then conditional licensing behavior, then the safety note. No wasted clauses, though the licensing field list makes the middle sentence dense.

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?

With no output schema, the description properly carries the return contract (note, not-found, conditional licensing object, delimiter wrapping). It covers the main cases well; only edge behavior like error/failure responses or note staleness is left implicit.

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?

Only one parameter and schema coverage is 100%, so the schema already documents the url field fully. The description adds no syntax or format detail beyond the schema, so baseline 3 applies.

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: return the vault note for a URL if already fetched, else a not-found result. An agent can distinguish it from fetch_url by the 'has been fetched' condition, though the description never names that sibling explicitly.

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 is a lookup that makes no vendor request when licensing is off or the publisher is unlicensed, which hints at 'check before fetching'. There is no explicit when-to-use/when-not or named alternative among the many siblings.

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