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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and network-fetch profile is covered. The description adds meaningful scope context (works for any PDS, not just Bluesky) but doesn't disclose fetch behavior, latency, or failure modes for an unresolvable origin.

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 tight sentences, front-loaded with the resource and its return fields, followed by scope and input format. No filler; each clause carries information.

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?

An output schema exists, so return values need not be spelled out, and the read-only/open-world annotations cover behavior. For a one-parameter read tool the description is sufficient, with only the sibling-routing guidance 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% and the single parameter is fully documented in the schema ('A PDS origin URL, e.g. https://pds.example.com'). The description restates the same input format without adding new meaning, so this is the baseline case where the schema does the heavy lifting.

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 (Describe) and resource (Personal Data Server) and enumerates exactly what is returned: DID, invite requirement, handle domains, ToS/contact links. The scope note 'Works for any PDS, not just Bluesky' sharpens it, though it doesn't explicitly distinguish itself from siblings like get_pds_directory_info or get_did_document.

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 purpose (given a PDS origin, describe that server), but there is no explicit when-to-use, when-not, or named-alternative guidance versus related tools such as get_pds_directory_info. Adequate minimum but leaves routing to inference.

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