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

With no annotations, the description carries full behavioral burden and delivers: it lists the return fields, defines the error lifecycle for a missing slug, and warns against guessing slugs. This is strong behavioral disclosure for a simple read tool.

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 compact and front-loaded with the core purpose, followed by terse guidance and error behavior. Every sentence carries meaningful information, and the structure flows logically from purpose to usage to fallback.

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 tool with no output schema, the description is complete: it enumerates return fields, explains the error response, and positions itself within the tool family. No critical behavioral or usage detail 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?

The input schema already documents the slug format and requiredness at 100% coverage. The description adds useful integration context ('only use slugs from prior tool results') and reinforces the 'never guess' rule, adding modest semantic value 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?

The description starts with a specific verb+resource: 'Fetch full details for one skill by slug.' It clearly distinguishes from sibling tools like search_skills and popular_skills by emphasizing single-skill detailed retrieval rather than list or search behavior.

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 states when to use this tool: 'Call AFTER search_skills or popular_skills when a user selects a specific result.' It also provides a negative directive ('do NOT batch-call for every item') and a concrete fallback path to search_skills on error, making usage guidance exceptionally clear.

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