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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered; the description adds the useful behavioral fact that this returns the *full* record (implied: more than the `search` summary) and lists the four record categories. It does not say what happens for an unknown or stale id, which is the main remaining gap.

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?

One sentence, front-loaded with the verb and resource, with the provenance constraint and the record-type enumeration packed into a single parenthetical. Nothing is wasted and nothing is buried.

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 one-parameter read-only fetch with full schema coverage and no output schema, the description supplies what the agent needs: where the id comes from and what class of record it returns. Only the not-found / invalid-id behavior is missing, which keeps it from a 5.

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% and the single id parameter already carries an example and its provenance ('An id from a `search` result'). The description restates that provenance but adds no format, validation, or failure semantics beyond the schema, so baseline 3 is correct.

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 pairs a specific verb ('Fetch') with a specific resource ('full SwiftProbate reference record') and enumerates the record types it can return, so the agent knows exactly what comes back. It falls short of a 5 because it does not distinguish itself from apparent look-alike siblings such as get_state_overview, lookup_county_guide, or lookup_institution_guide, which the enumerated record types overlap with.

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 states the precondition clearly: the id must come from a `search` result. That is real usage guidance. However, it gives no exclusion against the several siblings that appear to retrieve the same kinds of content directly by name/state, so an agent cannot tell from this text when fetch is preferred over get_state_overview or lookup_county_guide.

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