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

Annotations already provide readOnlyHint=true, idempotentHint=true, and destructiveHint=false, but the description goes further by adding concrete behavioral details: exact case-sensitive matching, unknown IDs returning a tool error, public/no-credentials access, 60-second feed caching, and errors for unavailable or invalid feeds. This goes well beyond the annotation coverage.

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?

The description is front-loaded with the core purpose and is reasonably compact. Most sentences earn their place, though the phrase about 'canonical sources, evidence clocks, publication state, release IDs, and limitations' is dense and somewhat jargon-heavy for a one-parameter retrieval tool, especially since an output schema is already present.

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 simple one-parameter read-only retrieval tool, the description is complete: it explains the ID provenance, exact matching, error behavior, caching, credentials, and how to route to search_stories when necessary. Since an output schema is present, the description does not need to enumerate return fields in more detail.

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?

The input schema already documents the id parameter thoroughly, including exactness, prefix, case-sensitivity, whitespace, and length constraints, so schema coverage is 100%. The description reinforces the exact-match behavior and mentions the unknown-ID error case, but it does not add substantial new parameter meaning beyond what the schema already provides.

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 states a specific verb ('Retrieve'), a specific resource ('one published story'), and the exact identifier type ('exact stable ID'). It also distinguishes itself from search_stories by emphasizing direct retrieval by ID rather than topic/title search, so an agent can clearly tell them apart.

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 explicitly says to 'Use search_stories first when you only know a title or topic,' naming the alternative and the condition that selects it. It also clarifies that unknown IDs return a tool error, which guides the agent to avoid calling get_story with approximate or unverified identifiers.

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