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

The annotations already declare readOnlyHint=true and openWorldHint=true, so the description does not need to repeat safety basics. It adds useful behavioral context by enumerating what the generated description includes and by disclosing the limitation that 'The camera framing is not in the link.'

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 front-loaded with the core transformation and has only two sentences. The long parenthetical list of encoded details is somewhat dense, but it earns its place because there is no output schema to document the return contents.

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 usefully explains the two returned text forms and enumerates the details included in the lesson-note description. It also notes a key limitation. Parameter details are covered by the schema, so the definition is largely complete for a read-only description 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 description coverage is 100%, so the schema already documents all three parameters, setting the baseline at 3. The description adds meaning about what the URL encodes and what it does not encode, but it does not expand on lang or time_zone beyond what the schema provides.

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 uses a specific transformation verb, 'Turns a Perigee link or embed URL ... into words,' and states the concrete outputs: one-sentence alternative text and lesson-note description. It references perigee_view as a source, which helps distinguish it from view-creation tools, though it does not explicitly distinguish itself from all siblings.

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 implied by the stated outputs: generating alt text for an image or iframe and descriptions for lesson notes. The description mentions links from perigee_view or shared links, but gives no explicit when-to-use/when-not-to-use guidance or named alternative tools.

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