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. The description adds real behavioral detail — single-file granularity and heading-plus-subsections scoping — but says nothing about truncation/failure behavior when a filename or section isn't found.

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?

A single sentence that front-loads the verb, the resource and the hard 'exactly one' constraint, with the optional mode trailing. No filler.

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 and returns are not the description's job; with 100% param coverage the remaining burden is modest. What's missing is minor but real: no hint about how a large file is continued across calls (offset chaining) or what happens for an unknown section/filename.

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 coverage is 100%, including offset semantics tied to 'the previous next_offset' and max_chars bounds, so the baseline is 3. The description adds one genuinely new fact — that a section read includes its subsections — but leaves the required trio (playbook_id, skill_id, filename) entirely to 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?

States a specific verb and resource ('Read exactly one skill file') with an explicit scope constraint plus an optional section-scoped mode. It doesn't distinguish itself from the nearby get_skill / get_playbook siblings, so an agent must infer that this reads file contents rather than skill metadata.

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 'exactly one skill file' phrasing implies one-file-per-call usage and the section mode implies a targeted-read path, but no sibling is named as an alternative and there is no when-not-to-use guidance. Pagination guidance exists only inside the schema's offset description.

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