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

Annotations already declare a safe, idempotent, non-destructive read, so safety is covered. The description adds real value beyond that: it discloses a data-completeness limitation (only Sun is fully populated, the other 8 planets return placeholder text) and names the cost tier. That limitation is exactly the kind of behavioral fact that changes how an agent presents results.

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?

Three sentences, front-loaded with the operation before the parameter encoding and the data caveat; the group and cost tags are compact trailing metadata. Every sentence earns its place; only mild redundancy in restating the parameter argument names.

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 structure needn't be explained, and annotations carry the safety profile. The description covers purpose, required parameter encoding, and the content-completeness caveat. The one remaining gap is not pointing to the sibling tool that serves full Lal Kitab readings, which is minor given the otherwise complete picture.

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 coverage is 50% and the two required integers carry no schema description, so the description must supply meaning. It does: planet is 0..6 with 11=Rahu and 100=Ketu, and house is 1..12, which the bare 'integer, min/max' schema does not convey. The optional fields and precision params are documented in the schema, so no extra compensation is needed there.

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+resource: a lookup of a (planet, house) placement rendered as a short summary per Lal Kitab. The name, title and description align, so an agent can tell this apart from broader LK tools like astroway_vedic_lal_kitab_lal_kundali or astroway_reports_lal_kitab. It stops short of explicitly naming those siblings, so it earns a 4 rather than a 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?

Usage is implied rather than stated: the caller provides planet and house to get a placement reading. The caveat 'Currently Sun-only full data; remaining 8 planets are placeholder text' is a genuine when-not-to-rely signal, which lifts it above bare implied usage. However, no alternative tool is named for full LK content, so routing remains inference-based.

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