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 the non-obvious access constraint (owner role plus sign-in) and a security-behavior warning about untrusted customer-typed text. That injection warning is genuine behavioral context an agent cannot get from structured fields. No statement about result volume, freshness, or ordering keeps it at 4.

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?

The access restriction and sign-in requirement are front-loaded in the first clause, and the safety note is isolated in its own sentence where it is easy to heed. The middle inventory is a long comma list, but each enumerated item tells the agent something it would otherwise have to discover by calling the tool, so it mostly earns its place.

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 parameters and no output schema, the description carries the full burden of describing what comes back, and it does so by naming each returned section. An agent knows enough to call it and interpret the response shape. Freshness, sort order, and any truncation limits are unstated, which is the remaining gap.

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?

The tool takes zero parameters and schema coverage is 100%, so there is no parameter meaning to add beyond the schema. The mention of block_id is output-side information routed toward unblock_time, which is a small bonus rather than parameter documentation. Baseline 4 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 enumerates exactly what the tool surfaces: upcoming bookings with counterparts, customer and address, unscheduled requests, time off, weekly hours, and unread notifications. That is far more specific than the title 'Upcoming schedule' and lets an agent distinguish this aggregate-view tool from single-purpose siblings like booking_status or find_times. It lacks an explicit verb ('returns'/'retrieves'), which is the only reason it falls short of 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?

It states a concrete prerequisite that determines whether the tool can be called at all ('Owners only (needs sign-in)') and gives one routing hint by noting that time-off entries carry a block_id for unblock_time. What is missing is any negative guidance about when not to use this broad snapshot versus narrower tools such as booking_status or find_times.

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