openemis_whoami

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

With no annotations, the description fully discloses behavioral traits: it never returns JWT, password, or tokens; it returns username, mode, timestamp, base URL, and testingMode flag; it explains permission scoping ('teachers see their schools...'); and it includes an instruction to refuse token requests. This is exemplary transparency for a whoami tool.

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 description is clearly structured with front-loaded purpose, usage guidance, disclaimers, and permission details. It is slightly longer than necessary but every sentence adds value; it could be condensed slightly without losing clarity.

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?

Given no output schema, the description covers all essential aspects: what is returned (username, mode, timestamp, base URL, testingMode flag), what is not returned (tokens), permission scoping, and an ethical directive. This is complete for a simple zero-parameter tool.

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 input schema has zero parameters and schema description coverage is 100%, so the baseline is 4. The description does not need to add parameter semantics, and it does not attempt to; it uses the available space for behavioral context instead.

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 clearly states the tool's purpose: 'Show which OpenEMIS user this MCP session is currently acting as.' It uses a specific verb ('Show') and resource ('user'), and distinguishes itself from sibling tools by focusing on identity rather than health, CRUD, or login/logout operations.

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?

The description provides explicit usage guidance: 'Use this at the start of a conversation, after any login/logout, and any time you need to verify identity before presenting data.' While it does not directly compare to alternatives, the contexts are clear and the instruction to use it for identity verification is sufficient for an experienced agent.

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