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

Annotations already declare readOnlyHint, non-destructive and closed-world, so the safety profile is covered. The description adds real behavioral context beyond that: explicit nulls rather than omissions, source links and reporting years, admissions caveats, and an explicit refusal to claim current seats or odds — telling the agent the data is dated and bounded.

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 and key are front-loaded in the first sentence, with data domains and return guarantees following. It is dense but nearly every clause carries information an agent needs; the enumeration of survey and metric domains is the only part that runs slightly long.

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?

With no output schema, the description takes on the burden of describing returns and does so: profile sections, history coverage through the latest reporting year, nulls, source links, and a canonical URL. For a single-parameter read tool this leaves nothing material an agent would need before calling 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 is one parameter at 100% schema description coverage, where the schema already explains the six-character DBN pattern and its provenance. The description's 'by DBN' adds no syntax, format, or normalization guidance beyond what the schema supplies, so it sits at the baseline.

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 ('Read one canonical school profile by DBN') and immediately scopes the contents: proprietary ratings, official academic metrics, surveys, demographics, enrollment history, Regents results. The phrase 'one canonical profile' distinguishes it from search_schools (discovery) and compare_schools (multi-school comparison) without needing to name them.

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?

Usage is only implied: the tool is keyed by a single DBN, and the schema notes the DBN comes 'from search results', which hints that discovery happens elsewhere. It never explicitly says when to prefer this over compare_schools or that search_schools should be run first to obtain a DBN, and it states no exclusions.

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