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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds genuinely new behavioral context beyond that: the data provenance ('what the owner recorded') and an access restriction ('Owner only') that the annotations do not express.

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 with no filler; the access constraint is placed last where it reads as a quick qualifier. The opening is a noun phrase rather than an action statement, which slightly weakens front-loading for a tool with an implicit verb.

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 one-parameter read with no output schema and strong annotations, the description covers what the data is, its granularity ('by campaign or ad and period'), its purpose, and its permission scope. It could say more about the period concept, but nothing needed to invoke the tool 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 coverage is 100% for the single project_id parameter, and the schema itself points to dosai_list_projects for the value. The description adds no additional parameter meaning, so the baseline 3 applies.

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 identifies the resource precisely — advertising spend recorded by the owner, broken down by campaign or ad and period — which an agent can distinguish from the write-side sibling dosai_add_ad_spend. It never states an explicit retrieval verb ('list/read'), so the read action is only implied by the tool name rather than the prose.

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?

'Used for the cost of a lead in analytics' gives one concrete use context, and 'Owner only' scopes the audience, but there is no explicit when-to-use vs. alternative (e.g., 'use dosai_add_ad_spend to record spend'). Usage is implied rather than directed.

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