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

With no annotations provided, the description carries the full behavioral disclosure burden. It discloses the per-request cost and the exclusivity constraint, and the verb 'Get' implies a read-only operation. However, it does not mention error handling, response format, or what happens if both or neither identifier is supplied.

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 concise sentences front-load the core purpose and immediately follow with cost and a critical usage constraint. Every sentence contributes useful information with no redundant 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?

For a single-post retrieval tool with no output schema and no annotations, the description adequately covers the core need: how to identify the postregation and what to expect. It could be more complete by noting the return shape or error behavior, but this is 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 the baseline is 3. The description adds meaningful parameter guidance by explicitly stating that exactly one of url or post_id must be provided, which is not encoded in the schema's required 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?

The description clearly states the tool 'Get a single Bluesky post by URL or ID', identifying a specific verb, resource, and input method. It is distinct from sibling tools like bluesky_post_comments or bluesky_user_posts, though it does not explicitly name those alternatives.

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 description gives clear context: use this tool to fetch one specific post using either a URL or an AT URI. It also provides a crucial usage rule—'Provide exactly one of url or post_id'—but does not explicitly discuss when to choose this over sibling post-related tools.

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