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

Annotations already establish readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behaviour: text responses are returned as bounded ordered chunks with a continuation token, binary responses are returned as a download descriptor for the host to fetch and verify, and paths are archive-relative rather than URLs or filesystem paths — a meaningful security constraint. It stops short of stating error cases or chunk-size defaults.

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?

Three dense sentences, front-loaded with the core action and followed by return-shape and path-safety constraints in a logical order. No filler, though the chunking instruction is packed tightly enough that it could be split for easier parsing.

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?

With no output schema and five parameters, the description carries the return-value burden and does so: it distinguishes text-chunk responses from binary download descriptors and explains how to reassemble a full document. What remains missing is error behaviour (e.g. revision mismatch or path not found) and a default for limit, which are relevant for a revision-pinned reader.

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 only 40% (only offset and revision_sha256 are annotated), so the description must compensate — and it partly does: it pins revision_sha256 to an 'exact skill revision', constrains path to archive-relative form, and implies limit/offset drive the bounded chunking. It adds nothing about slug's format or the meaning/limits of limit beyond what the schema's numeric bounds already show, leaving the compensation incomplete.

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 — 'Read one inventoried resource at an exact skill revision' — and scopes retrieval to a single artefact at a pinned revision. It never names a sibling such as get_skill or get_item, so the agent still has to infer which tool returns skill metadata versus a file inside the skill, which keeps it at a 4 rather than a 5.

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?

It gives usable procedural guidance for the pagination loop ('follow next_offset until null and verify full character coverage') and clarifies that binary content is not returned inline. It provides no when-to-use/when-not-to-use guidance relative to the many sibling retrieval tools (get_skill, get_item, fetch, search_library), so alternatives must be inferred.

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