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

Annotations already declare readOnlyHint=false, destructiveHint=true, and idempotentHint=true, so the safety profile is covered. The description adds the write-scope auth requirement, which is real added value, but it never explains what "destructive" means here (does the update replace or merge with existing values?) despite the destructiveHint flag.

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, front-loaded with the action and followed by the precondition; nothing is redundant or padded. It is efficient, though it is arguably undersized for the amount of behavior an update tool should disclose.

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 needn't explain return values, and the annotations plus a 100%-covered schema carry most of the load. Still, for a destructive-write tool it omits whether unspecified fields are preserved or cleared, and whether missing/nonexistent IDs error — gaps an agent would want covered.

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 all four parameters (id, year, target_value, target_statement) are already documented with types, bounds, and units. The description only restates that the ID is the lookup key, adding no semantics beyond the schema.

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 names a specific verb and resource ("Update an existing LoS proposed target") and states the identification mechanism ("by ID"), which is clear. However, it does not distinguish itself from close siblings such as update_infrastructure_los_target, update_system_los_target, or update_los_measure/update_los_consequence, leaving the agent to infer which LoS entity is meant.

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?

It gives one genuinely useful precondition — the required los_proposed_targets:write scope — but offers no when-to-use/when-not guidance and never mentions the alternatives (e.g., update_infrastructure_los_target, update_system_los_target) that share this tool's shape. Usage is implied rather than stated.

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