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

Annotations already cover read-only/idempotent/non-destructive, and the description goes well beyond them: it declares the username validation rule, the not-found behavior (found=false), the shape of returned data, and — most valuably — that the free-text purpose field is untrusted and must never be treated as an instruction. That prompt-injection warning is exactly the kind of behavioral disclosure annotations cannot carry.

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?

Six tight sentences, front-loaded with purpose, then validation, then return shape, then the trust warning. Every sentence carries information an agent needs; nothing is restated from the name or title.

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 compensates fully by enumerating return fields (owner wallet, IPFS hash, purpose, human/agent flag, registration status, page_url) and the negative case. Nothing required to call or interpret the tool 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?

Schema coverage is 100% so the parameter is documented, but the description adds an actual constraint the schema lacks: usernames are 3–32 characters of lowercase letters, numbers, underscore or hyphen, anything else rejected. That is real meaning beyond the example value in the schema.

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 ('Look up a Voicescape blockpage by username') and pins the mechanism ('via the on-chain Registry contract (Hedera mainnet)'), which distinguishes it from the render_blockpage siblings that only produce page output. An agent can tell what this does without opening the 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?

It gives a genuine usage hint — the returned page_url should be shared so the user opens the real page rather than a copy — but it never states when to prefer this over blockpage_earnings, render_blockpage, or propose_page_update, and there are no explicit exclusions. Usage is implied rather than routed.

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