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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is clear. The description adds useful behavioral context: it returns sessions with totals, supports date ranges and filters, and is for inspecting sessions. It doesn't contradict annotations and adds value beyond the structured fields.

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?

Four sentences, each earning its place: purpose, usage trigger, filter capabilities, and explicit alternative. Front-loaded with the core verb and resource, no redundant or vague language.

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 read-only list tool with an output schema, the description covers purpose, usage scenarios, filter options, and alternatives. It doesn't mention pagination details, but the limit parameter and output schema cover that. Minor gap: unclear if 'with totals' means aggregated rows or session-level data with a total field, but output schema would clarify.

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 parameters are already well-documented. The description echoes filter categories (date ranges, per-booth, payment status/channel) at a high level but doesn't add new semantics or clarify edge cases beyond the schema. Thus 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?

The description clearly states the tool lists photo sessions recorded on the operator's booths, with totals. It distinguishes from get_revenue_summary by explicitly directing money-related queries to that sibling tool, making the purpose unambiguous.

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?

Provides explicit when-to-use guidance: 'Call this when the operator asks how busy a booth has been, how many sessions ran in a period, or wants to inspect individual sessions.' Also names the alternative for money totals (get_revenue_summary), giving clear direction on tool selection.

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