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

Annotations already declare readOnly, idempotent, closed-world, non-destructive behavior, so the safety profile is covered. The description contributes one meaningful detail — it only explains *current public* codes, implying historical or non-published codes are out of scope — but says nothing about pagination or whether it returns one match or many.

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?

A single sentence with no filler, with the verb and the scope qualifier front-loaded. Its brevity is appropriate in form, though it is thin on substance rather than padded.

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 return values need not be described. However, with 5 parameters including an ambiguous free-text field and an opaque client_id, and with only two required inputs, the description leaves the agent guessing about how to construct a call and what a match means.

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 0% across 5 parameters, so the description must compensate and does not. Most critically, it never explains whether 'query' is a literal code value, a prefix, or free-text matching, nor what client_id represents — the single most consequential ambiguity for an 'explain' tool.

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 ("Explain") and resource (SACS codes), and enumerates the five code types that match the code_type enum, so the agent knows exactly what domain it covers. It doesn't explicitly contrast itself with any sibling, but no sibling appears to overlap this 'look up a code's definition' function.

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?

"current public" hints at scope (only current, published codes), but there is no statement of when to choose this tool over sacs_search_districts, sacs_query_financial_summary, or others, and no prerequisites or exclusions. The agent must infer usage from the name alone.

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