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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=true, so the safety profile is covered. The description adds one genuinely useful piece of context beyond them — the los_measures:write scope requirement — but says nothing about which fields get overwritten or what happens to omitted fields, which matters a lot for a destructive update.

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?

Two short sentences, zero padding, and the identify-by-ID constraint is front-loaded ahead of the scope prerequisite. Nothing could be removed without losing information.

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 16-parameter destructive update with a nested JSONB config object and no output schema, the description is too thin. It never explains update semantics (partial patch vs replacement), field-level validation surprises, or the consequences of the destructiveHint flag, so an agent would have to guess at the riskiest aspects of calling it.

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% across all 16 properties, including enums and bounds, so the schema carries the full parameter burden and the baseline is 3. The description adds no semantics beyond it — notably nothing about how the nested data_source_config object or the enum-valued type/category/data_source fields behave on update.

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 ('Update an existing LoS measure') and names the key ('by ID'), which distinguishes it cleanly from create_los_measure, delete_los_measure and get_los_measure. It does not explicitly name a sibling to contrast with, so it stops short of a 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?

Usage is implied rather than stated: 'existing' plus 'by ID' signals the tool requires a pre-existing record, and the scope requirement is a real prerequisite. However there is no explicit when/when-not guidance, no note on partial vs full updates, and no pointer to alternatives such as create_los_measure or bulk_update.

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