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

Annotations already declare readOnlyHint=false, destructiveHint=false and idempotentHint=true, so safety is largely covered. The description adds real behavioral value beyond that: partial-update semantics ('fields left out keep their values'), a non-obvious side-effect guarantee ('the notebooks themselves are not changed'), and the return payload shape despite there being no output schema.

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?

Front-loaded with the purpose and tightly packed: multi-field capabilities, patch semantics, return value, id source and the delete alternative are all covered in a few clauses. The trailing 'POST /collections/{collection}' is slightly redundant given the name and prevents a 5.

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 5-parameter mutation with no output schema, the description supplies both the return shape and the partial-update contract, and annotations carry the safety profile. Nothing an agent needs to call it correctly 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 description coverage is 100%, so the schema already documents every parameter, including the same-account constraint on addNotebooks and the non-deletion note on removeNotebooks. The description's 'fields left out keep their values' adds useful optionality semantics, but it is not per-parameter detail beyond the schema, so 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 (update) plus the exact resource and the distinct field-level operations available: rename, change emoji, add/remove notebooks. This lets an agent separate it from siblings like notebook_create_collection, notebook_delete_collection and notebook_rename_notebook.

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 the source of the required id ('from notebook_list_collections'), an explicit alternative for the different intent ('to remove the folder itself use notebook_delete_collection'), and the scope constraint (notebooks must be of the same account). The when-to-use-vs-alternative routing is fully explicit.

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