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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is fully covered by structured data. The description adds that output spans both future plans and past sessions, which is useful scope context, but leaves the ambiguous phrase 'sessions so far' unexplained and says nothing about ordering, limits, or response shape.

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 compact sentence with the payload front-loaded; every clause carries content (planned days, weekly rules, logged sessions). Slight loss for the vague phrasing 'the weekly rules' and 'the sessions so far', which costs precision without saving much space.

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 output schema, the description must carry the return-value burden, and it does sketch the three content areas. It still omits how many days are returned, what the weekly rules look like, and whether 'sessions so far' means completed activities or future entries, leaving gaps for a zero-required-parameter tool.

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%: the single optional 'today' parameter already documents its YYYY-MM-DD format, the pre-05:00 rollback rule, and that omission is allowed. The description adds nothing about this parameter, so the schema baseline of 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 names the resource clearly: the training schedule covering planned days (rest, long run, sport), the weekly rules, and sessions logged so far. It reads as a retrieval of the person's plan. However, it never distinguishes itself from the closely related sibling edit_schedule or today, so an agent cannot tell from the text alone whereas this is the read path.

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 when-to-use guidance: nothing says to pick this instead of edit_schedule (to modify) or today (for today's view). Usage must be inferred entirely from the noun phrase. This is a missed opportunity given three plausible sibling overlaps.

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