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

Annotations already cover the safety profile (readOnly, non-destructive, open world). The description adds genuinely useful behavior beyond them: newest-first ordering, a 50-per-page cap, and a per-page billing rate of $0.003, which matters for cost-aware callers. It stops short of pagination/cursor behavior, but the disclosure is strong.

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 tight paragraph that front-loads the purpose, then the return payload, then the cost/limit constraints. Every sentence carries information; 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?

No output schema exists, but the description enumerates the returned fields (handle, display name, DID, bio, verification, profile picture, join date), plus page size and billing. An agent has everything needed to invoke and interpret the result.

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 the baseline is 3, but the description adds the mutual-exclusivity rule ('provide exactly one' of URL or AT URI post_id) that the schema does not express. This is meaningful semantics beyond the structured fields.

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 ('Get the users who reposted a Bluesky post'), names the ordering ('newest first'), and is clearly distinguishable from siblings like bluesky_post_likes, bluesky_post_quotes, and bluesky_post_comments. An agent can select this without opening the schema.

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?

Usage is implied by the precise name and the 'provide exactly one' input constraint, so an agent knows the context. However, there is no explicit when-to-use/when-not guidance and no routing to alternative sibling tools (e.g. quotes or likes) for adjacent questions.

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