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

Annotations already declare readOnly, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely useful behavior: pagination ceiling (up to 50 posts per page), explicit billing ($0.003 per page, billed per page returned), and a surcharge for sentiment analysis.

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 tight sentences, front-loaded with purpose then return fields then controls and cost. No filler, though the returned-field enumeration is a long list rather than prose.

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, the description usefully enumerates what is returned (post text, author, date, engagement metrics, media, link cards, quoted posts), and cost/pagination behavior is stated. Nothing needed to call it correctly is missing.

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%, so the schema already documents every parameter including the enum and defaults. The description restates sort options and date-range limiting but adds no syntax, bounds, or format detail beyond the schema, so 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?

States a specific verb (Search) and resource (Bluesky posts) with a keyword-based scope, and clearly separates itself from sibling search_bluesky_users. An agent can identify the target 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?

Implied usage is clear (keyword search over Bluesky posts with sort and date range), but it never states when to prefer this over alternatives like search_bluesky_users or bluesky_user_posts, nor any exclusions. Adequate but with a clear routing gap in a large sibling set.

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