Skill costs (ranked)

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

No annotations are provided, so the description carries the full burden. It accurately discloses the ranking mechanism (token cost of always-loaded descriptions) and hints at the practical purpose (trimming). However, it does not specify output format, possible inclusion of skills without descriptions, or whether the list is sorted ascending/descending. Still, for a read-only analysis tool, the core behavior is sufficiently transparent.

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 two sentences with no filler. It front-loads the core purpose and immediately adds the actionable insight about trimming. Every sentence earns its place.

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 simple, read-only tool with two optional parameters and no output schema, the description is complete. It tells the user what the tool does, how it ranks skills, and why that is useful. The absence of detailed return value documentation is not problematic given the low complexity.

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 100% for both parameters (limit and filter), so the schema already documents their meaning. The description adds no extra parameter-specific context beyond the overall ranking concept. Baseline 3 is appropriate given the high schema coverage.

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 uses a specific verb and resource: 'Skills ranked by how many tokens their always-loaded description costs.' It clearly distinguishes the tool from siblings like context_budget or duplicate_skills by focusing on per-skill token cost ranking.

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 implies a clear use case: identifying which skills are most expensive in terms of always-loaded tokens, with the line 'The top of this list is where trimming pays off most.' It doesn't explicitly mention alternatives or when not to use it, but the context is clear and actionable.

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