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

Annotations already declare readOnlyHint and openWorldHint, but the description adds information annotations cannot express: the read is anonymous (no auth/permission prerequisite) and returns JSON. It also discloses the cardinality and quirks of the result set — 52 values including DC and a national US pseudo-state — which preempts an off-by-one assumption an agent would otherwise make when validating a state code.

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?

Three front-loaded clauses: what it returns, why to call it, then the operational facts (no params, anonymous JSON). The long sibling enumeration in the middle sentence is dense but functional — it is the routing information. Slight verbosity from listing six tool names inline rather than summarizing them.

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 zero-parameter reference lookup with an output schema already defined, the description covers everything an agent needs: access model, return fields, exact value count, the DC/national edge cases, and the reason to call it before the filtered siblings. Nothing material 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?

With zero parameters the baseline is 4, and the description confirms the empty-input contract explicitly ("takes no parameters") rather than leaving the agent to infer it from an empty schema. No per-parameter meaning is required.

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?

Opens with a specific verb+resource ("List the complete NFHS Network state and territory list") and immediately enumerates what each entry contains (code, name, slug). It is unmistakably a lookup/enumeration tool and cannot be confused with sibling tools like nfhs_schools or nfhs_events.

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 frames itself as a discovery tool and names the exact downstream consumers of its output: the state filters on nfhs_schools, nfhs_events, nfhs_highlights, nfhs_associations, nfhs_affiliates and nfhs_search. It also states the tool takes no parameters, so there is no ambiguity about what call shape to use before invoking the filtered siblings.

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