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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered and the description needn't repeat it. The description adds the id format convention and service provenance, but says nothing about behavior on a miss (error vs empty result) or what 'a package' record contains.

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?

Two short sentences, front-loaded with the action and key format, with the example immediately after. The 'Served by W3BS (https://w3bs.org)' line is mildly redundant with the [W3BS] prefix but adds provenance at low cost.

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, read-only lookup with full annotation coverage, the description provides the essential call contract (what to pass, in what format). The main gap is return shape, which matters slightly more because no output schema exists, but it is not a blocker for correct invocation.

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 0%, so the schema only says 'string, 3-200 chars'. The description compensates by defining the required format as a publisher-qualified id and supplying a concrete example, which is genuinely new meaning not present in the structured data.

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 ('Get one catalog package') plus the exact key it takes ('publisher-qualified id'), with a concrete example id, e.g. anthropic.com/claude-code. This implicitly separates it from list/browse/search siblings like w3bs_packages and w3bs_search, though no sibling is named 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 only implied: 'by its publisher-qualified id' hints that you should call this when you already know the exact id, but there is no explicit when-to-use vs when-to-use-an-alternative guidance (e.g. use w3bs_search when you only have a name).

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