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

With no annotations, the description carries the full burden and does disclose two useful traits beyond structured data: the call is free (no payment required) and the result set is complete (all 36 states + FCT), implying a static, non-paginated reference list. It also implies the return content (state-to-capital pairs). What it omits is trivial for a zero-parameter list — there is no mutation or auth to disclose.

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?

Two short sentences, zero waste, with the scope-defining content ('36 Nigerian states plus the FCT with their capitals') front-loaded before the cost note.

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?

No output schema exists, so the description has to convey the return shape, and it does (states with their capitals). For a zero-param, read-only reference tool that is nearly complete; only an explicit statement of the response structure (e.g. array of {state, capital}) 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?

The tool takes zero parameters, so no parameter semantics are needed; baseline is 4. The description correctly signals there is nothing to supply by framing it as an unfiltered 'list all'.

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 ('List all 36 Nigerian states plus the Federal Capital Territory with their capitals') with exact scope — the 36 states plus FCT — so an agent knows precisely what comes back. No sibling overlaps: the others are chain_* or ng_* validators/lookups, none of which enumerate states.

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: it is evidently a static reference lookup to be used when state/capital names are needed, e.g. to normalize input for ng_bank_validate or ng_identity_format. It states no explicit when-to-use or when-not-to-use condition and names no alternative.

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