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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds value beyond that by disclosing the timezone the results are rendered in, that ids are returned, and the default 30-day window — behavioral details not present in the annotations. It does not mention pagination or result caps.

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 front-loaded sentence carries the resource, scope, defaults, output shape, and timezone, followed by a short two-word sequencing clause. No filler and no repetition of schema-obvious details beyond what is needed.

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?

An output schema exists, so return values need not be explained, and the description still flags the key ones (ids, timezone). For a two-optional-param read with full annotation coverage, this is nearly complete; only pagination or volume expectations are unaddressed.

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%, and the schema already documents the YYYY-MM-DD pattern plus each parameter's default (today / 30 days after from). The description restates the default window and timezone semantics rather than adding new meaning, so the 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?

States a specific verb (List) and resource (time off and focus blocks) scoped to "the user's own," which distinguishes it from a broader calendar or schedule read. It also names output fields (ids) and rendering (profile timezone), so an agent knows exactly what comes back. It stops short of explicitly contrasting with sibling readers like schedule.read or calendar.read.

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?

"Read before availability.delete" gives one concrete workflow cue, which is genuinely useful sequencing guidance. However, there is no guidance on when to prefer this over other availability-related tools or what happens with no arguments beyond the default window. Usage context is implied rather than fully specified.

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