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

Annotations already cover read-only, idempotent, non-destructive, open-world behavior, and the description adds genuinely non-obvious traits beyond them: each call re-fetches the live sitemap, and releases older than ~48 hours will not be found. That staleness/failure mode is exactly the kind of context annotations cannot express.

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 with zero waste. The primary action and its source domain come first, followed by the sourcing hint and the staleness caveat in priority order.

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-parameter fetch tool with no output schema, the description covers action, source, and the key failure mode. It could briefly note what is returned (article content vs. metadata), but nothing essential for correct invocation 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?

Only one parameter and schema coverage is 100%, so the schema already documents 'url' fully. The description adds the source-domain constraint (einpresswire.com), which is minor value over the schema; 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 and resource ('Fetch one specific EIN Presswire release by its URL') and pins the source domain. It is clearly distinguishable from the sibling list/search tools (einpresswire_latest_releases, einpresswire_search_releases), which it names explicitly.

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?

Explicitly routes the agent: the URL comes 'as returned by einpresswire_latest_releases or einpresswire_search_releases', so the precondition is clear. It does not state when not to use it (e.g. for bulk retrieval), but the usage context is unambiguous.

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