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

No annotations are supplied, so the description carries the burden. It does disclose the key behavioral trait — the response contains only blocksCount and no block payloads — but says nothing about read-only nature, permissions, error behavior for a missing article, or filtering semantics, which is a meaningful gap for an unannotated 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?

Two short sentences, zero filler, and the distinguishing behavior is stated up front. Every clause 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?

Filtering is fully documented in the schema and an output schema exists, so return structure need not be explained. The description still notes that only blocksCount is returned, which is helpful; the only missing piece is error/precondition behavior, a minor gap given the tool's simplicity.

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%, so types, search, and article_id are all documented in the schema itself. The description adds only a cross-reference to get_article_blocks for parameter meaning, not any additional syntax or semantics, so the baseline 3 applies.

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?

A specific verb and resource (count article blocks) plus explicit scope (only blocks matching the filters). It names the sibling get_article_blocks and states the precise difference — same parameters, returns only blocksCount — so an agent can distinguish the two immediately.

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?

"Accepts the same parameters as get_article_blocks but returns only blocksCount, without the blocks themselves" effectively tells the agent when to pick this over the sibling: when only the count is needed. It does not spell out exclusions or preconditions (e.g. article must exist), so it stops short of a 5.

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