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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds one piece of behavioral context — that results are scoped to 'upcoming' sessions — but says nothing about ordering, pagination, or whether past sessions are excluded entirely.

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 short sentence with the key qualifier ('upcoming') front-loaded. Minimal waste, though the vague 'and their places' tail could be replaced with something more informative or dropped.

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 simple two-parameter read-only list tool with full schema coverage and annotations, the description is adequate but leaves the ambiguous 'places' term and the level/branch filtering behavior unexplained. No output schema exists, so a note on what a 'trial session' record contains would have helped.

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 both parameters (level, branch) are already documented in the schema. The description adds no meaning beyond that — it never mentions that results can be narrowed by level or branch, which is the main filtering capability an agent would want to know about.

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 (upcoming trial sessions) and clarifies with examples (open houses, assessment days), but the verb is only implied by the name and the trailing phrase 'and their places' is ambiguous — it could mean venue locations or available seats. It also does not distinguish this from close siblings like list_trial_seats or hold_trial_seat.

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 guidance on when to call this versus list_trial_seats, list_trial_sessions-adjacent tools, or add_trial_session. The word 'upcoming' implies a filter but no conditions, prerequisites, or exclusions are stated.

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