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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds rich behavioral context beyond that: it specifies the exact return structure (object with slug, name, tagline, skills, free_skill), explains error behavior (returns error object, never protocol error), explicitly says 'Every call is read-only and idempotent', and advises that retrying after input correction is safe. No contradiction with annotations.

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 description is well-structured and front-loaded with the core purpose. Each sentence adds value: the count, included skills, cost, argument count, return format, slug usage hints, and exclusions. The error-handling section is a bit lengthy but informative. Could possibly be tightened slightly, but overall efficient for the richness of 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?

Given the tool's zero parameters, rich annotations, and presence of an output schema, the description fully compensates for any gaps. It covers purpose, return value structure, error behavior, usage boundaries, and retry safety. It is complete for an agent to select and invoke correctly, even for a complex server with multiple sibling tools.

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?

The schema has 0 parameters and is already fully covered (100%). The description adds no param info because there are none to document. Baseline is 4 for 0 params, but the description proactively confirms 'Takes no arguments', which provides clarity and pre-empts any confusion, justifying a 5.

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?

The description clearly states the tool lists 'the 7 outbound products with their included skills' and explicitly notes it is 'FREE' and takes no arguments. It distinguishes itself from siblings by listing what the returned data is (metadata only) and what it is not (no persona text, no skill instructions), and names alternatives like get_free_skill and search_catalog.

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?

The description explicitly tells when to use this tool ('when the caller wants to see what this server covers'), and when not to ('Not for keyword search across the whole 138-product catalog'), naming a specific alternative (catalog server's search_catalog). It also warns against using it for instructions that get_free_skill provides.

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