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

Beyond the readOnly/idempotent annotations it discloses content boundaries ('metadata only - no persona text and no skill instructions'), cost ('FREE'), and a non-standard error contract: no protocol errors, instead an {'error': ...} object, plus that retry after correction is safe. That is behavior an agent cannot infer from annotations alone.

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-loaded with the verb, scope, and a sample return object, then usage and exclusions. Slightly longer than needed: the return-shape example duplicates the output schema, and the read-only/idempotent/retry sentence restates annotation content.

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?

An output schema exists, yet the description still sketches the object shape and explicitly flags what is absent (persona text, skill instructions), which is exactly the distinction an agent needs before chaining to get_free_skill. Error semantics and sibling routing are both covered.

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?

Zero parameters, so the schema has nothing to explain; the description confirms 'Takes no arguments,' which closes the loop. No further parameter meaning is needed, though it also spends words on the empty argument list.

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 ('List every product in the Personal Suite line with its included skills') and bounds the scope to 20 products. It explicitly carves itself out from catalog-wide keyword search and from instruction-fetching tools, so an agent can pick it over siblings without opening a 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?

Gives a positive trigger ('Use when the caller wants to see what this server covers'), explicit exclusions ('Not for keyword search across the whole 138-product catalog... search_catalog does, and not for instructions... get_free_skill'), and names the downstream tools that consume the returned slugs.

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