Count favorite media

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read profile is covered. The word 'exact' hints that these are authoritative totals rather than paginated estimates, which is genuinely useful, but nothing is said about authentication requirements, whose favorites are counted, or failure modes when unauthenticated.

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 tight sentence with the outcome front-loaded and no filler. Every word earns its place and there is nothing to trim.

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 the description does not need to explain return values, and with no parameters and read-only annotations the surface is small. It is nearly complete, with only the implicit assumption that counts are scoped to the authenticated user left unstated.

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, so there is nothing for the description to clarify; the baseline for a no-parameter tool is 4. No misleading hints about inputs are present.

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 gives a specific verb ('Return') and a precise resource ('exact saved track, album, artist, playlist, and video counts'), enumerating all five favorite categories. This separates it from the many list_favorite_* siblings, which return items rather than aggregate numbers. It stops short of explicitly naming that alternative, so it is clear but not fully differentiated.

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?

Usage is implied rather than stated: an agent can infer this is the tool to call when only totals are needed instead of full lists. No when-not conditions, no named alternatives (e.g. 'use tidal_list_favorite_tracks if you need the items themselves'), and no note that it reflects the authenticated user's favorites. Minimum viable guidance.

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