Change the roles on a DataLens collection

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

Annotations already declare readOnly=false, destructive=false, openWorld=true and idempotent=false, so the safety profile is covered. The description adds genuinely non-obvious behavior: this is a partial/delta update where unnamed roles are left untouched, which is important context an agent cannot derive from the schema or hints. It omits permission requirements and error behavior, keeping it below 5.

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?

A single compact sentence with the partial-update constraint front-loaded and no filler. Every clause earns its place.

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 two-parameter mutation with annotations covering safety and no output schema to explain, the description supplies the one behavior that matters most (incremental role changes). Missing only permission requirements and failure semantics, which is a minor gap.

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 collection_id, deltas, action, roleId and subject. The description's phrase 'roles not named stay as they are' echoes the schema's ADD/REMOVE delta semantics without adding syntax or format detail. Baseline 3 applies when the schema does the heavy lifting.

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 states a specific verb pair and resource: 'Give or take away roles on a collection.' That is enough to distinguish it from the workbooks/sharedentries variants of the same operation, which target different resources. It stops short of naming the sibling tool explicitly, so it lands at 4 rather than 5.

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?

There is no statement of when to use this tool versus alternatives such as datalens_collections_access_bindings_list (to inspect current roles) or the workbooks/sharedentries binding updaters. The agent must infer the use case from the verb alone. No prerequisites or exclusions are given.

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