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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real behavioural context beyond them: it names the source status vocabulary (OBSERVED, DEGRADED, NOT MONITORED), mentions 'last good check' freshness, and notes the presence of an explicit not-covered list and publication rules. It stops short of describing freshness semantics or how stale a 'last good check' might be.

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 purpose is front-loaded in the first clause, and the trailing 'Takes no arguments' is a useful, short operational note. The middle enumeration of returned content is dense and reads as a list-in-prose, but each item corresponds to a distinct coverage dimension rather than padding.

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 the description does not need to specify return structure, and it correctly focuses on scope and the when-to-use rule instead. For a zero-argument, read-only introspection tool this gives the agent everything needed to decide to call it.

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?

There are zero parameters and the description confirms this with 'Takes no arguments', which prevents an agent from hunting for optional filters. The baseline for a no-parameter tool is 4; nothing further is needed.

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 opens with a specific verb and object — 'Describe exactly what Seraphix covers and what it does not' — and enumerates the dimensions of coverage (companies, dossier status, sources, tiers). That framing is clearly distinct from the record-retrieval siblings like get_company and search_records, which return data rather than coverage metadata.

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?

It gives an explicit when-to-use rule: 'Call this before concluding that something is absent.' That is a concrete decision rule an agent can act on without inference, and for a coverage/schema-introspection tool there is no meaningful exclusion case that needs stating.

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