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

Annotations cover readOnly=false, destructive=false and openWorld=true, but the description adds real value beyond them: edits to a published lesson save live so students see changes immediately, confirmation is on by default and can be disabled, and the user's Cotlet API key is required. These are genuine behavioral facts an agent needs. It does not contradict the destructiveHint=false annotation.

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 first three sentences restate the same operation twice: 'Rename a lesson or replace the text of its Text & Image block' is then repeated as 'Renames a lesson and replaces the text of one Text & Image block,' and the 'other blocks untouched' point is made twice as well. The redundant sentences dilute an otherwise well front-loaded opening.

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?

For a mutation tool with no output schema, the description covers purpose, side effects (live save on published lessons), confirmation behavior and auth requirements, which is enough for an agent to call it correctly. Only minor gaps remain, such as how toggling confirmation off actually works.

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 five parameters, including the block_id default. The description clarifies that title renames the lesson and body_markdown replaces the block text, but this largely mirrors the schema and adds no new syntax or format detail. Baseline 3 is appropriate.

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 pair (rename a lesson, replace text of its Text & Image block) and the exact resource scope, plus explicitly says other blocks (video, PDF, audio, quiz) are untouched. An agent can distinguish it from create_lesson, publish_lesson and get_lesson 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?

Gives clear context on what the tool will and won't affect ('Other blocks stay as they are'; lists block types not touched), which implies when it is and isn't the right choice. It stops short of naming a sibling alternative for cases it can't handle, so it is clear context without explicit routing.

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