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

Annotations only declare readOnly=false, openWorld=true, idempotent=false, destructive=false; the description adds substantial behavior beyond that: a verification email is sent, the API key (edk_...) stays inactive until the link is clicked, and the key then surfaces in the portal. This async, state-dependent side effect is exactly the context an agent needs and is not derivable from the annotations.

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 sentences, purpose front-loaded, with the consequence (key unlocks other tools) stated early and prerequisites last. Dense but every clause carries information; the final requirements sentence is long though still load-bearing.

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 and no annotations covering the return value, the description still explains the outcome (key appears in the portal) and the activation flow. What is missing is only granular detail like retry/re-request behavior, which is minor for a signup 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?

Schema coverage is 50%, so the description must compensate — and it does, enumerating all four required inputs (email, 8+ char password, company name, license acceptance) and supplying the license URL that the boolean refers to. This adds meaning (what must be accepted and where) beyond the bare schema types.

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 (create) and resource (Engagemii data account), and differentiates from siblings by explaining the account it creates unlocks search_companies and data_records. An agent can place this action relative to the other tools without opening a schema.

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 clearly conveys the context of use — sign up to obtain a key that unlocks search_companies and data_records — and describes the prerequisite flow (email verification before the key activates). It does not explicitly state when NOT to use it (e.g. if the user already has an account), so it stops short of full when/when-not guidance.

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